“And as by the earthquake the middle portion of the roof and the higher parts had been destroyed, the king made it stronger, and raised it to a greater height. Anthemius was then dead, but the young man Isidorus and the other craftsmen, turning over in their minds the previous design, and comparing what had fallen with what remained, estimated where the error lay, and of what kind it was. They determined to leave the eastern and western arches (_apsides_) as they were. But of the northern and southern (arches) they brought towards the inside, that portion of the building which was on the curve.[59] And they made these arches wider so as to be more in harmony with the others, thus making the equilateral symmetry more perfect. In this way they were able to cover the measurelessness of the empty space, and to steal off some of its extent to form an oblong design. And again they wrought that which rose up over it in the middle, whether orb (_kuklos_), or hemisphere, or whatever other name it may be called. And this also became more straightforward and of a better curve, in every part agreeing with the line; and at the same time not so wide but higher, so that it did not frighten the spectators as formerly, but was set much stronger and safer.” [Illustration: FIG. 4.--Longitudinal Section, having regard to Dome as first built.] _Evagrius._--This historian was born in 536 A.D.[60] at Epiphania on the Orontes. In his _Ecclesiastical History_ we learn of the suffering caused by the invasion of Chosroes in 540. From this time all Syria was continually disturbed, and the educated Christians fell back more and more on Constantinople. Evagrius came to Constantinople in 589, though he returned to Antioch afterwards. His history commences with the Council of Ephesus in 431 and extends to the year 593. He says[61]:-- “In the city of Constantinople Justinian constructed many churches of wonderful beauty in honour of God, and the saints--among them was a great and incomparable work of a kind that none like it was ever remembered--the great church of S. Sophia; which excelling in beauty, far surpasses power of description. “As far as I can I will explain it. The nave (_naos_) of the temple has a dome (_tholos_) over it spreading its weight on four arches, raised to such a height, that to those looking from below it is difficult to see the whole hemisphere. And those who are above, however bold they are, never dare to bend over and look on to the ground: and the arches are open from the base up to their crown. On the right and left however, opposite to one another, are ranged columns of Thessalian marble. These with other neighbouring columns carry upper chambers, which offer a place to lean forward for those who wish. Here it is that the empress is wont to attend service on festal days.